<?xml version="1.0" encoding="utf-8"?>  
<rotate xmlns:android="http://schemas.android.com/apk/res/android" android:interpolator="@android:anim/linear_interpolator"  
    android:fromDegrees="0" android:toDegrees="+360" android:duration="1000"  
    android:pivotX="50%" android:pivotY="50%" android:repeatCount="infinite" />  